Cerebral vascular accident, a disease commonly known as "stroke" remains the third leading cause of death, and probably constitutes the single largest category of long-term disability in this country. In spite of current medical knowledge and available treatments, a major central system vascular occlusion is quickly attended by irreversible damage to the affected brain region(s). A "completed stroke" is manifest by a fixed and permanent neurological deficit. Millions of dollars have been expended in stroke research and care by federal and private agencies without a single substantial gain in our present chemotherapeutic abilities for a completed stroke.
In each of the aforementioned patents and applications, however, the present applicant has disclosed and claimed a novel nutrient formulation for circulation through cerebro-spinal fluid pathways, and systems and methods for using the same to treat central nervous tissue hypoxic-ischemic conditions. Applicant has recognized that there is a therapeutic time window through which neurons can be reached and resuscitated.
In accordance with the inventions disclosed and claimed in the aforementioned patents and applications, a synthetic cerebro-spinal fluid is circulated through the cerebro-spinal fluid passageways immediately after a stroke. Specifically, the oxygenated nutrient is circulated through those cerebro-spinal fluid passageways which contact brain and spinal cord tissue. According to these methods, treated tissues exhibit a substantially improved ability to resist and/or repair damage which would otherwise result from vascular occlusion.
The circulation apparatus disclosed in the aforementioned patents and applications comprises a reservoir containing a nutrient emulsion; means for delivering the nutrient emulsion at preselected flow rates; an oxygenation means for equilibriating the nutrient emulsion to desired gaseous tension levels; heat exchanger and/or cooling unit means for selectively controlling the temperature of the nutrient emulsion; filter means for cleansing the nutrient emulsion; and circulation monitoring means for ensuring the desired circulation flows are maintained within the system. Specifically, in carrying out the method described and claimed in the aforementioned patents and applications, the nutrient emulsion is delivered from the nutrient emulsion reservoir to the lateral ventricle of the brain. Injection of the nutrient input stream directly to the brain permits the oxygenated nutrient emulsion to come into contact with the subarachnoid spaces, miniature Virchow-Robins spaces, cerebral and cord surfaces, and cerebral ventricles. Circulation of the nutrient input stream through at least a portion of the cerebro-spinal pathway may be accomplished by withdrawing fluid from the spinal subarachnoid space, or alternatively, from the cisterna magna.
While the aforementioned system and method have been found to be particularly useful in the treatment of stroke, treatment must be begun within a therapeutic time window immediately following the onset of the stroke. Because time is so critical, treatment must be administered by paramedics and emergency personnel or, alternatively, by emergency room physicians and staff. Since the treatment described in the aforementioned patents and applications requires the injection of oxygenated nutrient emulsion directly into the lateral ventricles of the human brain and the withdrawal of that nutrient emulsion from the subarachnoid space or the cisterna magna, it should be clear that the procedures used in the treatment are not ones which paramedics and emergency personnel or even most emergency room personnel are familiar with.
Specifically, the treatment requires that an aperture be formed in the cranium and that a catheter be inserted directly through the aperture of the skull and thereafter through the soft tissue of the brain into the lateral ventricles. Such techniques are difficult enough for skilled neurosurgeons and are typically beyond the ken of paramedical personnel.